452
M. Honda
since lycopene is abundant in the tomato, which is one of the most popular and
widely consumed vegetables in the world, the carotenoid is easily ingestible. Thus,
it is considered that the marketplace is expected to further expand.
18.1.2 β-Carotene
β-Carotene, which has two unsubstituted β-ionone ring half-sites and 11 conjugated
double bonds, is a red-orange pigment found in many vegetables such as carrots and
spinach. β-Carotene is an important vitamin A source for human and the method for
industrial synthesis was established in half a century ago, so that the basic research
of the carotenoid has been done since quite a long time ago compared to other
carotenoids. Several studies reported that β-carotene would reduce risk of some
cancers such as stomach cancer and skin cancer (Blot et al. 1993; Köpcke and Krutmann 2008). On the other hand, some large-scale intervention studies of β-carotene
supplementation has not been shown any beneficial effect on cancer prevention or
shown an adverse effect on the incidence of lung cancer and gastric cancer with 20–
30 mg of β-carotene per day in smokers and workers exposed to asbestos (Albanes
et al. 1996; Omenn et al. 1996). Several researchers indicated that one of the largest
factors of that would excess intake of β-carotene: the normal intake of carotenoids
is approximately 1.5 mg per day for people in the United States (Druesne-Pecollo
et al. 2010). In fact, Siems et al. (2005) indicated that, obviously, on certain conditions of high-dose carotenoid supplementation, both the antioxidant and prooxidant reactions arise. Therefore, smokers and workers exposed to asbestos should
avoid high-dose β-carotene supplementation. β-Carotene would be effective against
erythropoietic protoporphyria. Ample studies have demonstrated that the oral dose
of β-carotene relieves the photosensitivity associated with the disease (MathewsRoth et al. 1974, 1977). In addition, the dietary β-carotene could have an age-related
macular degeneration-preventing effect (West et al. 1994). The simultaneous ingestion of β-carotene, zinc, and antioxidants such as vitamin C and vitamin E would
further enhance the preventive effect, i.e., trial participants who received a daily highdose supplement of β-carotene (15 mg), vitamin C (500 mg), vitamin E (400 IU),
and zinc (80 mg) had an approximately 25% reduced risk of progression from relatively advanced early age-related macular degeneration stages to late age-related
macular degeneration (Age-Related Eye Disease Study Research Group 2001). On
the other hand, Tan et al. (2008) indicated that higher β-carotene intake may be
associated with a risk increase of age-related macular degeneration. From the above,
β-carotene shows various health benefits, especially high provitamin A activity, but
it is considered important to be aware of proper intake.
M. Honda
since lycopene is abundant in the tomato, which is one of the most popular and
widely consumed vegetables in the world, the carotenoid is easily ingestible. Thus,
it is considered that the marketplace is expected to further expand.
18.1.2 β-Carotene
β-Carotene, which has two unsubstituted β-ionone ring half-sites and 11 conjugated
double bonds, is a red-orange pigment found in many vegetables such as carrots and
spinach. β-Carotene is an important vitamin A source for human and the method for
industrial synthesis was established in half a century ago, so that the basic research
of the carotenoid has been done since quite a long time ago compared to other
carotenoids. Several studies reported that β-carotene would reduce risk of some
cancers such as stomach cancer and skin cancer (Blot et al. 1993; Köpcke and Krutmann 2008). On the other hand, some large-scale intervention studies of β-carotene
supplementation has not been shown any beneficial effect on cancer prevention or
shown an adverse effect on the incidence of lung cancer and gastric cancer with 20–
30 mg of β-carotene per day in smokers and workers exposed to asbestos (Albanes
et al. 1996; Omenn et al. 1996). Several researchers indicated that one of the largest
factors of that would excess intake of β-carotene: the normal intake of carotenoids
is approximately 1.5 mg per day for people in the United States (Druesne-Pecollo
et al. 2010). In fact, Siems et al. (2005) indicated that, obviously, on certain conditions of high-dose carotenoid supplementation, both the antioxidant and prooxidant reactions arise. Therefore, smokers and workers exposed to asbestos should
avoid high-dose β-carotene supplementation. β-Carotene would be effective against
erythropoietic protoporphyria. Ample studies have demonstrated that the oral dose
of β-carotene relieves the photosensitivity associated with the disease (MathewsRoth et al. 1974, 1977). In addition, the dietary β-carotene could have an age-related
macular degeneration-preventing effect (West et al. 1994). The simultaneous ingestion of β-carotene, zinc, and antioxidants such as vitamin C and vitamin E would
further enhance the preventive effect, i.e., trial participants who received a daily highdose supplement of β-carotene (15 mg), vitamin C (500 mg), vitamin E (400 IU),
and zinc (80 mg) had an approximately 25% reduced risk of progression from relatively advanced early age-related macular degeneration stages to late age-related
macular degeneration (Age-Related Eye Disease Study Research Group 2001). On
the other hand, Tan et al. (2008) indicated that higher β-carotene intake may be
associated with a risk increase of age-related macular degeneration. From the above,
β-carotene shows various health benefits, especially high provitamin A activity, but
it is considered important to be aware of proper intake.